Effect of different dental composite resins on the polymerization process

Dental composite resins possess good esthetic properties, and are currently among the most popular dental restorative materials. Both organic and inorganic phases might influence the material behavior, the filler particle features and rate are the most important factors related to improvement of the mechanical properties of resin composites. Thus, the objective of this study was to evaluate the effect of three different composite resins on the polymerization process by Vickers hardness test. The samples were prepared using three different composite resins, as follow: group I-P-60 (3M/ESPE); group II-Herculite XRV (Kerr), and group III-Durafill (Heraeus-Kulzer). The samples were made in a polytetrafluoroethylene mould, with a rectangular cavity measuring 7 mm in length, 4 mm in width, and 3 mm in thickness. The samples were photo-activated by one light-curing unit based on blue LEDs (Ultrablue III-DMC/Brazil) for 20 and 40 s of irradiation times. The Vickers hardness test was performed 24 h after the photo-activation until the standardized depth of 3 mm. The Vickers hardness mean values varied from 158.9 (+/- 0.81) to 81.4 (+/- 1.94) for P-60, from 138.7 (+/- 0.37) to 61.7 (+/- 0.24) for Herculite XRV, and from 107. 5 (+/- 0.81) to 44.5 (+/- 1.36) for Durafill composite resins photo-activated during 20 s for the 1st and 2nd mm, respectively. During 40 s of photo-activation, the Vickers hardness mean values were: from 181.0 (+/- 0.70) to 15.6 (+/- 0.29) for P-60, and from 161.8 (+/- 0.41) to 11.2 (+/- 0.17) for Herculite XRV composite resins, for the 1st and 3th mm, respectively. For Durafill composite resin the mean values varied from 120.1 (+/- 0.66) to 61.7 (+/- 0.20), for the 1st and 2nd mm, respectively. The variation coefficient (CV) was in the most of the groups lower than 1%, then the descriptive statistic analysis was used. The Vickers hardness mean values for Durafill were lower than P-60 and Herculite XRV composite resins for 20 and 40 s of irradiation time. The polymerization process was greatly affected by the composition of the composite resins.

Spiral drawing during self-rated dyskinesia is more impaired than during self-rated off

Background: A mobile device test battery, consisting of a patient diary collection section with disease-related questions and a fine motor test section (including spiral drawing tasks), was used by 65 patients with advanced Parkinson's disease (PD)(treated with intraduodenal levodopa/carbidopa gel infusion, Duodopa®, or candidates for this treatment) on 10439 test occasions in their home environments. On each occasion, patients traced three pre-drawn Archimedes spirals using an ergonomic stylus and self-assessed their motor function on a global Treatment Response Scale (TRS) ranging from -3 = very 'off' to 0 = 'on' to +3 = very dyskinetic. The spirals were processed by a computer-based method that generates a "spiral score" representing the PD-related drawing impairment. The scale for the score was based on a modified Bain & Findley rating scale in the range from 0 = no impairment to 5 = moderate impairment to 10 = extremely severe impairment. Objective: To analyze the test battery data for the purpose to find differences in spiral drawing performance of PD patients in relation to their self-assessments of motor function. Methods: Three motor states were used in the analysis; OFF state (including moderate and very 'off'), ON state ('on') and a dyskinetic (DYS) state (moderate and very dyskinetic). In order to avoid the problem of multiple test occasions per patient, 200 random samples of single test occasions per patient were drawn. One-way analysis of variance, ANOVA, test followed by Tukey multiple comparisons test was used to test if mean values of spiral test parameters, i.e. the spiral score and drawing completion times (in seconds), were different among the three motor states. Statistical significance was set at p<0.05. To investigate changes in the spiral score over the time-of-day test sessions for the three motor states, plots of statistical summaries were inspected. Results: The mean spiral score differed significantly across the three self-assessed motor states (p<0.001, ANOVA test). Tukey post-hoc comparisons indicate that the mean spiral score (mean ± SD; [95% CI for mean]) in DYS state (5.2 ± 1.8; [5.12, 5.28]) was higher than the mean spiral score in OFF (4.3 ± 1.7; [4.22, 4.37]) and ON (4.2 ± 1.7; [4.17, 4.29]) states. The mean spiral score was also significantly different among individual TRS values of slightly 'off' (4.02 ± 1.63), 'on' (4.07 ± 1.65) and slightly dyskinetic (4.6 ± 1.71), (p<0.001). There were no differences in drawing completion times among the three motor states (p=0.509). In the OFF and ON states, patients drew slightly more impaired spirals in the afternoon whereas in the DYS state the spiral drawing performance was more impaired in the morning. Conclusion: It was found that when patients considered themselves as being dyskinetic spiral drawing was more impaired (nearly one unit change in a 0-10 scale) compared to when they considered themselves as being 'off' and 'on'. The spiral drawing at patients that self-assessed their motor state as dyskinetic was slightly more impaired in the morning hours, between 8 and 12 o'clock, a situation possibly caused by the morning dose effect.

Maintaining life satisfaction: the role of positive cognitive bias

Recent research into population standards of life satisfaction has revealed a remarkable level of uniformity, with the mean values for Western populations clustering at around three-quarters of the measurement scale maximum. While this seems to suggest the presence of a homeostatic mechanism for life satisfaction, the character of such a hypothetical device is uncertain. This paper proposes that well-being homeostasis is controlled by positive cognitive biases pertaining to the self. Most particular in this regard are the positive biases in relation to self-esteem, control and optimism. Past controversies in relation to this proposition are reviewed and resolved in favour of the proposed mechanism. The empirical data to support this hypothesis are discussed in the context of perceived well-being as an adaptive human attribute.

Limnology and culture-based fisheries in non-perennial reservoirs in Sri Lanka

This study was carried out to investigate the possibility of using the limnological characteristics of non-perennial reservoirs in Sri Lanka for the future management of culture-based fisheries. Forty-five reservoirs were randomly selected to study their limnology, out of which 32 were stocked with fish fingerlings of Chinese and Indian carps, tilapia and freshwater prawn at stocking densities ranging from 218–4372 fingerlings ha−1. Of these, 23 reservoirs were harvested at the end of the culture period (6–10 months). Thirteen limnological parameters were measured during the water retention period of each of the 45 reservoirs between November 2001 and January 2004. The mean values of the limnological parameters were used to ordinate the reservoirs through principal component analysis. Ordination showed a productivity gradient among reservoirs where Secchi disc depth, total phosphorus, chlorophyll-a, inorganic turbidity and organic turbidity were identified as key factors. The total fish yield of culture-based fisheries was positively correlated to the scores of the first principal component axis. This study reveals that it is possible to classify non-perennial reservoirs in Sri Lanka based on the above limnological parameters in order to develop culture-based fisheries and that they could be applicable in comparable water bodies elsewhere in the tropics.

Culture-based fisheries in non-perennial reservoirs of Sri Lanka: influence of reservoir morphometry and stocking density on yield

Culture-based fish yield in non-perennial reservoirs of Sri Lanka was related to reservoir morphometry and stocking density. The reservoirs were stocked mainly with fingerlings of one Chinese and three Indian major carp species, common carp, Cyprinus carpio L., and the genetically improved farmed tilapia strain of Nile tilapia, Oreochromis niloticus (L.), at four pre-determined species combinations and a range of stocking densities [SD (fingerlings ha⁻¹)]. Twenty-three reservoirs were harvested successfully at the end of the culture period of 2002–2003. Basic limnological and morphometric parameters, including shoreline development (D_L) and shoreline area ratio (R_LA), were estimated for each of the 23 reservoirs. Bray–Curtis similarity and non-metric multidimensional scaling using mean values of limnological data revealed that reservoirs could be ordinated into two major clusters, one with intact sample distribution due to similar trophic characteristics and the other with scattered sample distribution. Reservoirs in the cluster with similar trophic characteristics showed significant correlation (P < 0.05) between R_LA and total fish yield (Y). A multiple regression equation, Y = −693 + 4810 R_LA + 0.484 SD, was generated to estimate fish harvest in relation to SD.

A grouping journals using multi-dimensional perceptual criteria of North American marketing academics

This paper seeks to develop groupings of journals (A, B, C) using multi-dimensional perceptual rankings, based on North American respondents’ evaluation of a journal’s prestige, contribution to theory, contribution to practice and contribution to teaching. Nonparametric comparisons of criterion mean values indicate that there are generally statistically significant correlations between criteria. Cluster analysis identifies A, B, and C 'categorisations' of journals are different in regards to all four evaluative criteria.

Slow component of VO2 during level and uphill treadmill running : relationship to aerobic fitness in endurance runners

The aim of this study was to compare the oxygen uptake (VO^sub 2^) slow component (SC) during level and uphill running in endurance runners, and to identify associations between the SC and the following aerobic fitness indicators: peak VO^sub 2^, running speed associated with the peak VO^sub 2^ (Vpeak), running speed at the lactic threshold and the VO^sub 2^ fraction elicited at the lactic threshold. Fourteen male endurance-trained runners underwent several 6-min bouts of level (LTR) and 10.5% uphill treadmill running. VO^sub 2^ SC was calculated as the difference between mean VO^sub 2^ during the 6th and the 3rd minutes. The highest mean values for the SC were 181.9±240.2 mL*min^sup -1^ for level running at ~94% peak VO^sub 2^ and 105.4±154.6 mL*min^sup -1^ for uphill running at ~90% peak VO^sub 2^. The SC observed during the last bout of the LTR correlated with peak VO^sub 2^ and with Vpeak (-0.71 and -0.76, P<0.05, respectively). The results show that for endurance-trained runners the magnitude of the SC is not affected by the treadmill gradient and that within a homogeneous sample of endurance-trained runners the SC does not correlate with indicators of aerobic fitness.

Nutrition, growth and production of Cherax Destructor Clark, 1936 (Decapoda, Parastacidae)

In this study the nutrition, growth and production of C. destructor was examined. Selected nutritional requirements of juvenile animals were determined under controlled conditions with the aim of developing a pelleted diet for use in hatcheries, nurseries and growout situations. The best developed diet was assessed for its potential as a supplementary feed for animals cultured in earthen environments. The protein requirements were first determined simultaneously with an evaluation of the effect of replacing animal protein (fishmeal) by soybean meal. Juveniles were reared communally for 59 d on isoenergetic diets containing 15-30% protein and graded levels of soybean meal (0-60%, of protein). When soybean meal was included at a level of 40-60%, growth was reduced relative to that achieved with control diets containing 15% and 20% protein, but this was not the case at a 20% soybean meal substitution level. A two-way interaction occurred between dietary protein and soybean meal content. Higher protein feeds enabled higher soybean meal inclusion levels without significantly affecting growth. Protein increases of 5% produced better growth at the 40% and 60% soybean meal substitution levels. This effect was less pronounced in the control and the 20% soybean meal diets. Carcass %protein increased and %lipid decreased as dietary protein increased. A similar effect occurred by increasing the soybean meal level to 60%. No obvious trend in carcass moisture, energy, and ash occurred. A protein requirement of 30% was apparent when fish meal and soybean meal were included in diets at levels of 20% and 24% (dry matter) respectively. Alternative protein sources to soybean meal were subsequently identified. Juveniles were maintained for 12 weeks on isoenergetic diets containing 30% protein and differing in the primary source of protein used, with meat, snail, soybean, yabby, and zooplankton meals comprising the major protein ingredient. No significant difference occurred in mean weight (MW), percentage weight gain (%WG), SGR or survival among diets. Food conversion ratios (FCR) were low, with a minimum value of 0.95 for the snail-based diet. The apparent net protein utilisation (ANPU) varied from 29.6% (zooplankton-based diet) to 41.2% (snail-based diet). Carcass composition varied with diet, with the greatest difference occurring in carapace colour. Animals fed the zooplankton-based diet developed the strongest, most natural pigmentation. A new combination of previously used protein-based ingredients was subsequently tested with reference to two yabby species, Cherax albidus and Cherax destructor, that were grown simultaneously in identical conditions. Juvenile male animals were reared individually for 20 weeks on isoenergetic diets containing 15% or 30% protein with fish meal, soybean meal, yabby meal and wheat products forming the basis of the diets. C albidus grew the fastest and utilised the food the most effectively. Carcass composition was influenced by diet with the 30% protein diet resulting in an increase in carcass protein and ash and a decrease in carcass lipid and energy relative to the low protein diet. Carcass moisture and calcium were not affected by diet. The intermoult period (IP) was highly dependent on the premoult weight (W) but the mean moult increment (WI, as weight) was independent of the PM. The orbital carapace length (OCL) and the abdominal length (ABL) %moult increments generally declined with an increase in PM whereas the propus length (PL) %moult increment generally increased. The IP, WI, %OCL, %ABL, and %PL moult increments varied according to diet and to species. Elevated dietary protein caused a reduction to the IP (for similar sized animals) by 11 d and 7 d and an increase to the WI by 85% and 81% in C. albidus and C destructor respectively. Dietary induced morphological changes also occurred. Animals of a standard OCL (both species) had significantly larger abdomens when fed the higher protein diet. Growth on the best developed diet was compared to the growth obtained on a natural diet of freshwater zooplankton. Juveniles were reared individually for 12 weeks on the two diets. The MW, %WG and SGR were higher for the zooplankton diet. Carcass composition was influenced by diet and the zooplankton fed animals had a higher carcass %protein, %lipid, %ash and %fibre content and were more richly pigmented than animals fed pellets. The IP and the WI were highly dependent on the PM and varied according to diet; feeding with zooplankton reduced the IP by 1.2 days and increased the WI by 13.7% compared to pellets. Nutrient digestibility was determined for the pelleted diets evaluated in the growth trials. Protein digestibility (PD) and dry matter digestibility (DMD), using chromic oxide (Cr2O3) as an exogenous marker, were high for all diets, at around 93% and 83% respectively. Ash digestibility varied considerably from 17% to 73% for the snail and yabby meal diets respectively. Crude fibre digestibility was around 50% and probably indicates cellulase activity. Alternative markers to Cr2O3 were evaluated. Ash was considered to be the most suitable alternative to Cr2O3, providing a reasonable, albeit lower, estimate of nutrient digestibility. Cr2O3 and ash were preferentially excreted whereas fibre was retained in the digestive system for a longer period, consequently, the collection of a particular fraction of the deposited faeces (late or early) substantially affected the digestibility coefficients. In earthen-based environments, animals fed the best developed diet were compared to animals cultured using a forage crop of clover (Trifolium repens). Three supplementary feeding strategies representing varying levels of management intensity were evaluated in a series of trials conducted in ponds and pond microcosms. Growth on pellets consistently exceeded that obtained with the forage crop, with final MW being 67-159% higher than that using clover and appeared to be the result of direct pellet consumption and from a pellet fertiliser effect (on the sediment). Within-pond DMD and PD were high and similar for each treatment (DMD = 51-58%; PD = 89-92%). In the control pond, DMD and PD increased with each successive flood. The faecal egestion rate (PER) decreased with each successive flood in all ponds, and is negatively related to animal weight and to foregut fullness (FF) according to power curves. FF was consistently lowest in the control pond. Mean FF was 48.5%, 62.3%, and 26.7% for the pellet, crop and control ponds respectively. FF increased to the third flood in each pond. The foregut protein content was high in all samples and the mean values were 33.9%, 32.7% and 35.6% for the pellet, crop and control ponds respectively. Foregut ash was highly variable within each pond and is inversely related to the foregut protein content. In the control and pellet ponds the highest foregut ash content occurred during flood 1. The culture system (aquaria or pond) strongly influenced the composition of the foregut content. The foregut of animals fed the manufactured diet (B2) in ponds contained approximately 176% more ash and 5% more protein than the foregut of animals fed in bare-bottom tanks. The FF of the tank fed animals was approximately 45% higher than the FF of pond fed animals after a similar feeding period. Base-line yields for extensive production systems appeared to be around 400kg ha-1. The supplementary addition of T. repens produced yields of approximately 635kg ha-1 (in ponds) to around 1086kg ha-1 (in tanks). The sequential addition of cut-clover to tanks stimulated growth to levels approaching those achieved on pellets. Yabbies stocked into ponds at 15-20 m-2 with a mean weight of 2.67g and fed a 30% protein pelleted diet for 100 d, resulted in a yield of approximately 1117kg ha-1, but only 2% of the population were above a marketable size of 50g. The feed utilisation indices were better for animals reared on pellets in bare-bottom tanks than in earthen environments, indicating some degree of pellet wastage when natural feeds are simultaneously present. High apparent food conversion ratios and low protein efficiency ratios occurred when the forage crop was provided. A considerable quantity of the dry matter and protein content of the forage crop was either inefficiently utilised or directed into other production pathways. Sowing a forage crop into pond microcosms to which a pelleted diet was also provided, did not enhance growth performance. Pelleted feed inputs at a rate of approximately 129g m-2 to 198g m-2 (dry matter) and 38g -2 to 64g m-2 (protein) over 70-100 d resulted in acceptable growth and feed utilisation indices for animals reared in ponds and pond microcosms. Forage crop inputs of approximately 533g m-2 to 680g m-2 (as dry matter) or 84g m-2 to 177g m-2 (as protein) over a 70-100 d period produced reasonable growth rates but poor feed utilisation indices. Low inputs of dry matter (from 113-296g m-2) and protein (from 24-54g m-2) from clover were sufficient to maintain high growth rates in pond microcosms for around 28 d. In ponds, a very low level of 21g m-2 (dry matter) and 4.3g m-2 (protein) was sufficient for around 3 weeks. Forage depletion appeared to occur beyond week 3-4 and was probably a major growth limiting factor. The mean hepatosomatic index (HSI) was 9.44, 7.68, and 6.79 for the pellet, crop, and control ponds respectively. The relationship between hepatopancreas weight and overall animal weight was significantly different between treatments. The hepatopancreas of pellet-fed animals had the highest %lipid and lowest %ash, %protein, %carbohydrate and %moisture content. In terms of absolute quantities, the only major difference in hepatopancreas composition between treatments occurred for lipid and dry matter content. The hepatopancreas of the pellet-fed animals was a cream/cream-yellow colour and was very fragile, whereas in the other ponds it was a more ‘natural’ bright yellow colour and was structurally more robust. C. destructor has a capacious foregut, being approximately 5 times the volume of similar sized Penaeids. The foregut volume (V, ml) of the yabby is related to animal weight (W, g) according to V = 0.048 W0.9543. Animals that were starved for 96 h and then fed diet B2 were almost completely foil after 30 min. The ‘apparent enzymatic response’ of animals fed various natural and artificial diets in tanks was evaluated. Nutrient processing time and the enzymatic response following ingestion appeared to be regulated by the chemical and physical properties of the diet. For the natural feeds, foregut protein was 1.2% higher (for zooplankton) and up to 300% higher (for detritus) than dietary protein, whereas ash was 7.5% higher (zooplankton) and 46-63% lower (detritus) than dietary ash. For animals fed diet B2 after 48 h without food, FF was approximately half that of 96 h starved animals after a similar feeding period but foregut protein and ash contents were similar. Finally, the physiological and morphological attributes elucidated in this study are discussed with reference to the ecology of the yabby. High growth rates, excellent feed utilisation indices and high digestibility coefficients for a wide range of diet-types illustrate nutritional flexibility. A capacious foregut, a large hepatopancreas with a high energy storage capacity, the ability to partition and preferentially excrete the low nutrient value inorganic component of the diet, the capacity to alter body form, nutrient processing time and enzymatic secretions in relation to diet-type, and modified behaviour according to feed availability also demonstrate plasticity/adaptability/flexibility. The combined effect of these important characteristics ensures survival in environments that may be adverse and highly variable in terms of nutrient availability. Collectively the morphological and digestive traits elucidated in this study reflect the generalist-type nature of C destructor and indicate that a polytrophic classification still seems appropriate. Several priority areas for further nutrition research are identified and recommendations are made regarding the best-practices to use in the commercial culture of the yabby. Of paramount importance is the further clarification of the nutritional requirements and feeding preferences of animals in various phases of development.

Australian teaching and learning centres through the eyes of their directors : characteristics, capacities and constraints

This paper is based on research to identify common factors that contribute to the effective strategic leadership of teaching and learning centres. The second of three phases of data collection involved a survey of Directors of Australian teaching and learning centres. The data collected were quantitatively analysed using a range of descriptive, parametric and non-parametric techniques. Based on a response rate of 81.6 percent, we present a contemporary, comprehensive and representative quantitative snapshot of Australian teaching and learning centres, as seen through the eyes of their Directors. The time since last restructure, incumbency of the current Director and total Directorship experience of the current Centre Director all have mean values of ‘sometime in the previous one to three years’. Most Centres would consider their work in the areas of ‘recognition and reward’ and ‘professional development of staff’ as high impact functions, and they would be pleased with their efforts in the former area, and wish to perform better on the latter. The principal constraint identified by Centres was ‘lack of staff time’, both in the Faculties and in the Centre, to engage in teaching and learning improvement activities. Overall, Centres feel well included in relevant university committees and other activities.

Leptin in depressed women : Cross-sectional and longitudinal data from an epidemiologic study

Background There is conflicting evidence regarding levels of leptin in depression. In this study we aimed to investigate the relationship between serum leptin level and depression in a community sample of women using both cross-sectional and longitudinal data.

Methods From among 510 women aged 20–78 yr, 83 were identified with a lifetime history of major depressive disorder or dysthymia, ascertained using the Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition (SCID-I/NP). Serum leptin levels were measured by radioimmunoassay. Medication use and lifestyle were self-reported and body mass index (BMI) determined from measures of height and weight.

Results Using multiple linear regression, serum leptin levels were greater among women with a lifetime history of depression compared to women without any history of depression, independent of BMI. Adjusted geometric mean values of serum leptin were 16.37 (95%CI 14.70–18.23) ng/mL for depressed and 14.46 (95%CI 13.79–15.16) ng/mL for non-depressed women (P = 0.039). The hazard ratio (HR) for a de novo depressive disorder over five years increased 2.56-fold for each standard deviation increase in log-transformed serum leptin among non-smokers and this was not explained by differences in BMI, medications or other lifestyle factors (HR = 2.56, 95%CI 1.52-4.30). No association was observed for smokers.

Limitations There is potential for unrecognised confounding, recall bias and transient changes in body composition.

Conclusion Women with a lifetime history of depression have elevated levels of serum leptin, and elevated serum leptin predicts subsequent development of a depressive disorder.

'Mind and body' : a lifestyle programme for people on antipsychotic medication

Rationale Psychiatric illnesses such as schizophrenia and their treatments have consequences in terms of lifestyle, diet and weight.

Aims and objectives ‘Mind and Body’ is a 10-week programme of weekly sessions aimed to improve the health status of people treated with second generation antipsychotic medications.

Methods The programme focuses on a range of lifestyle strategies including diet and exercise and was conducted at a Community Health Centre by professionally qualified staff. Between 2002 and 2006, 50 participants enrolled in, and 30 completed the programme. Measures of body weight, health status (Short Form-36) and blood markets (plasma glucose, haemoglobin A1c and lipid profile) were collected at commencement and completion of the programme.

Results A modest improvement was demonstrated in mean values for the majority of measures collected.

Conclusions A lifestyle program for people treated with antipsychotic medications is achievable and may be worthwhile although gains may be modest.

Takeaway food consumption and cardio-metabolic risk factors in young adults

Background/objectives: Takeaway food consumption is positively associated with adiposity. Little is known about the associations with other cardio-metabolic risk factors. This study aimed to determine whether takeaway food consumption is associated with fasting glucose, insulin, lipids, homeostasis model assessment (HOMA) and blood pressure.

Subjects/methods: A national sample of 1896, 26–36 year olds completed a questionnaire on socio-demographics, takeaway food consumption, physical activity and sedentary behaviour. Waist circumference and blood pressure were measured, and a fasting blood sample was taken. For this analysis, takeaway food consumption was dichotomised to once a week or less and twice a week or more. Linear regression was used to calculate differences in the adjusted mean values for fasting lipids, glucose, insulin, HOMA and blood pressure. Models were adjusted for age, employment status, leisure time physical activity and TV viewing.

Results: Compared with women who ate takeaway once a week or less, women who ate takeaway twice a week or more had significantly higher adjusted mean fasting glucose (4.82 vs 4.88 mmol/l, respectively; P=0.045), higher HOMA scores (1.27 vs 1.40, respectively, P=0.034) and tended to have a higher mean fasting insulin (5.95 vs 6.45 mU/l, respectively, P=0.054). Similar associations were observed for men for fasting insulin and HOMA score, but the differences were not statistically significant. For both women and men adjustment for waist circumference attenuated the associations.

Conclusion: Consuming takeaway food at least twice a week was associated with cardio-metabolic risk factors in women but less so in men. The effect of takeaway food consumption was attenuated when adjusted for obesity.

Daily eating frequency and cardiometabolic risk factors in young Australian adults : cross-sectional analyses

Eating frequency may be important in the development of overweight and obesity and other cardiometabolic risk factors; however, the evidence is inconsistent. The aim of the present study was to examine the associations between the number of eating occasions and cardiometabolic risk factors in a national population-based sample of young adults. A cohort of 1273 men and 1502 women, aged 26–36 years, completed a meal pattern chart to record when they had eaten during the previous day (in hourly intervals). The total number of eating occasions was calculated. Diet quality was assessed, waist circumference was measured and a fasting blood sample was taken. Dietary intake was compared with the Australian Guide to Healthy Eating. The associations between the number of eating occasions and cardiometabolic risk factors were calculated using linear regression. Analyses were adjusted for age, education and physical activity. Most men ate three to five times per d and most women ate four to six times. The proportion of participants meeting dietary recommendations increased with the number of eating occasions. For men, an additional eating occasion was associated with reductions in mean values for waist circumference ( − 0·75 cm), fasting glucose ( − 0·02 mmol/l), fasting insulin ( − 0·34 mU/l; 2·04 pmol/l), TAG ( − 0·03 mmol/l), total cholesterol ( − 0·08 mmol/l) and LDL-cholesterol ( − 0·06 mmol/l). Adjustment for waist circumference attenuated the results. Significant trends were not observed for women. In conclusion, a higher number of eating occasions were associated with reduced cardiometabolic risk factors in men. Many associations were mediated by waist circumference.

Measuring walking within and outside the neighborhood in Chinese elders : reliability and validity

Background : Walking is a preferred, prevalent and recommended activity for aging populations and is influenced by the neighborhood built environment. To study this influence it is necessary to differentiate whether walking occurs within or outside of the neighborhood. The Neighborhood Physical Activity Questionnaire (NPAQ) collects information on setting-specific physical activity, including walking, inside and outside one's neighborhood. While the NPAQ has shown to be a reliable measure in adults, its reliability in older adults is unknown. Additionally its validity and the influence of type of neighborhood on reliability and validity have yet to be explored. Methods : The NPAQ walking component was adapted for Chinese speaking elders (NWQ-CS). Ninety-six Chinese elders, stratified by social economic status and neighborhood walkability, wore an accelerometer and completed a log of walks for 7 days. Following the collection of valid data the NWQ-CS was interviewer-administered. Fourteen to 20 days (average of 17 days) later the NWQ-CS was re-administered. Test-retest reliability and validity of the NWQ-CS were assessed. Results : Reliability and validity estimates did not differ with type of neighborhood. NWQ-CS measures of walking showed moderate to excellent reliability. Reliability was generally higher for estimates of weekly frequency than minutes of walking. Total weekly minutes of walking were moderately related to all accelerometry measures. Moderate-to-strong associations were found between the NWQ-CS and log-of-walks variables. The NWQ-CS yielded statistically significantly lower mean values of total walking, weekly minutes of walking for transportation and weekly frequency of walking for transportation outside the neighborhood than the log-of-walks. Conclusions : The NWQ-CS showed measurement invariance across types of neighborhoods. It is a valid measure of walking for recreation and frequency of walking for transport. However, it may systematically underestimate the duration of walking for transport in samples that engage in high levels of this type of walking.

Reliability and validity of the Alberta context tool (ACT) with professional nurses: Findings from a multi-study analysis

Although organizational context is central to evidence-based practice, underdeveloped measurement hindersitsassessment. The Alberta Context Tool, comprised of 59 items that tap10 modifiable contextual concepts, was developed to address this gap. The purpose of this study to examine the reliability and validity of scores obtained when the Alberta Context Tool is completed by professional nurses across different healthcare settings. Five separate studies (N = 2361 nurses across different care settings) comprised the study sample. Reliability and validity were assessed. Cronbach's alpha exceeded 0.70 for9/10 Alberta Context Tool concepts. Item-total correlations exceeded acceptable standards for 56/59items. Confirmatory Factor Analysescoordinated acceptably with the Alberta Context Tool's proposed latent structure. The mean values for each Alberta Context Tool concept increased from low to high levels of research utilization(as hypothesized) further supporting its validity. This study provides robust evidence forreliability and validity of scores obtained with the Alberta Context Tool when administered to professional nurses.